Water injection device for concrete mixers



\ Dec. 19, 1950 L. G. HILKEMEIER 2,534,445

WATER INJECTION DEVICE FOR CONCRETE MIXERS Filed Jan. 11, 1949 LOUIS 6.HILKEMEIER spy/7Z4 M ATTORNEY IN V EN TOR. v

Patented Dec. 19, 1950 UNITED STATES .ATENT OFFICE WATER INJECTIONDEVICE'FOR CONCRETE. l'iHXERS Louis. G. Hilkemeier, Greenfield, Wis.,assignor to Chain Belt Company, Milwaukee, Wis, a. corporation ofWisconsin Application January 11, 1949, Serial No. 70,174

3 Claims.

2 paratus are illustrated in the accompanying drawings, together with anovel disposition of a plurality oi'valvesfor improving water dispersionin the drum; In the drawings:

The invention is especially suited for concrete 5 Fig. 1 is a sideelevation, partly in section, of mixers of the type mounted on trucks,wherein a truck mounted concrete mixer drumv with the the concrete ismixed as it is hauled. water injection devices arranged therein;

It is a characteristic of such truck mounted Fig. 2 is an enlarged crosssectional view of one concrete mixers-that the dry materials loaded intoof the water injection devices; the drum occupy a large proportion ofthe drums 10 Fig. 3 is an end view of the apparatus shown volume, andthe most eilective manner of intron g; 2;'and ducing water into thematerials in the drum is to Fig. 4 is a view similar to Fig. Showing adispose the water valve so that at least during a modification of theapparatus. portion of the mixing period, it is beneath the Asillustrated in thedrawings, themixer drum level of the materials in thedrum. Hence dur- 15 II is of the type that its frame may be mounted ingrotation of the drum, concurrently with the on the rear of atruck; Thedrum is provided introduction of Water, rapid and efficient mixing withspiral blades I 2 attached to its innerwall's, may result. which elevateand tumble the materials to be Utilization of the most eltiectiveposition for wamixed. The materials may be introduced into terintroduction has resulted in a problem of 20 the drum through a hatchopening in the side According to thepresent invention, a tubular fdischarge conduit is provided within the drum having one end closed andthe other end communicating with a source of water under pressure.Tightly enveloping a section of the conduit and having one end clampedthereon is a sleeve of yieldable, deformable material, enclosing aseries of lateral apertures in the conduit through which the water mayflow prior to its passage between the sleeve and the conduit en route tofinal discharge from adjacent the other end of the sleeve. The sleeveand the conduit are separated around the apertures to provide areservoir for the. water flowing through the apertures, enabling thepressure on the sleeve to increase because of the increased sleeve area,and thereby expanding the adjacent portion of the sleeve radially. Suchexpansion produces axial movement of the free end of the sleeve relativeto the conduit, which is effective in breaking upany concrete that mayset around the orifice and also loosens and enables discharge of anygrout or fine material that may have become lodged between thejuxtaposed surfaces of the sleeve and the conduit.

Two embodiments of such water injection anof the drum, and afterthebatch is mixed, concrete is discharged through an axial opening Marranged at the rear end ofthe drum. The forward end of the drum iclosed and carries a sprocket l5 which is drivenby a chain from asuitable source of power to thereby rotate the drum and its contents.

Extending axially'through theclosed end of the drum is the Water pipe[6-, the forward end of which communicates with a water pump ll whichderives its supply from the exterior water tank Hi. The pump is of acapacity to develop considerable pressure on the water leaving it andentering the drum.

The pipe it connects to an elbow fitting I9 which extends generallyradially from a point on the axis of the drum spaced a short distanceinwardly from the closed; forward drum head. The outerend of the elbowfitting i9 is provided with a flange 20 which maybe threaded into theend of the elbow l9. Secured to flange 2B isa second elbow fitting 2|which has a flanged inner end 22 to which the flange 20 is bolted orotherwise secured.

The elbow fitting 21 has a straight outer portion 23 arranged to beclosely adjacent the side wall of the drum and parallel to one of thespiral mixing blades 12. The valve at the end of the straight portion 21is thus closely adjacent the inside wall of" the drum, behind one of theblades, and points in the direction of the blade (i. e. diagonallytoward the rear of the drum), so that waterflowing therefrom may flowperipherally of the drum in the path ofthe blade as the latter churnsthrough the materials in the drum.

As illustrated in Fig. 2, the outer end of the straight portion 23 ofthe elbow shaped conduit 22 is closed by the plug 24 which may be weldedor otherwise secured to the conduit. Up the pipe a distance from theclosed end, are a series of apertures 25 in the conduit, spacedcircumferentially around the conduit. Preferably there are several rowsof apertures with the individual apertures in each row offset withrespect to those in the other row so as to arrange them closer together,and to provide greater area for the passage of water therethrough.

A molded rubber sleeve 26 having an inside diameter slightly less thanthe outside diameter of the pipe 23 is forced over the closed end of theipe until the end 2? of the sleeve approximately coincides with theclosed end of the pipe. The inner end of the sleeve is engaged by theclamping ring 2e which is tightened by the bolt 29 and nut 3B threadedthereon to prevent displacement of the sleeve and also to prevent escapeof water from this end of the sleeve. The free end of the sleeve 27 hasa snug fit on the pipe to prevent concrete from entering between thesleeve and the conduit, when the pump i! is not in operation.

Enclosing the apertures 25, an annular recess 3| is provided on theinside of the sleeve 25. This recess is of a width sufiicient toaccommodate the apertures and of a depth somewhat less than thethickness of the sleeve. Preferably the thickness of the sleeve in backof the recess is the same as its thickness through other cross sections,and therefore the outside surface of the sleeve protrudes in the regionof the recess.

When sufiicient pressure of water is developed by the pump ii, the wateris forced through the apertures 25 into the recess 3| and thence betweenthe sleeve 2t and the conduit 23 to emerge at the end 2'5 of the sleeve.The initial water pressure built up in the reservoir provided by therecess 3i causes the sleeve to expand, drawing the discharge end 2'!axially of the pipe to the dotted line position shown in Fig. 2.Relative movement between the end of the sleeve 2! and the conduit 23loosens concrete accumulations that might be tending to seal theorifice, and also scrubs and loosens any fines that may have workedtheir way back from the orifice into the space between the sleeve andthe conduit. Once loosened, they are flushed out by the water passingthrough the orifice.

It is essential to have adequate aperture area to permit free passage ofwater through the wall of the conduit and that the rubber sleeve beelastically deformable to a marked extent. It has been found desirableto provide an aperture area in excess of the total cross sectional areaof the conduit, and to employ a rubber having a Durometer rating betweenso and 4.0 to obtain the desired results with the valve disclosed.

Similar results, though not quite as effective, may be obtained by themodified nozzle illustrated in Fig. 4. Instead of providing a recess, asat 35 in the sleeve, an annular depression or recess 32 is provided onthe outside periphery of the pipe, the width of the depression beingsuch as to communicate with all the apertures 25, and its depthproviding a reservoir similar in volume to the reservoir provided by therecess 3! in the sleeve shown in Fig. 2. In this modification, the crosssection of the sleeve is constant throughout its length, but the spacewhich is provided by the depression 32 between the sleeve and conduitincreases the area of the sleeve subject to pressure, and enables thetotal pressure acting on the adjacent portion of the sleeve to increaseto the point where the sleeve expands, thereby shortening the length ofthe sleeve, and producing axial movement of the sleeve relative to thepipe.

A further feature of the present invention consists in providing asecond water orifice on the radial portion of the elbow fitting l9, asillustrated in Fig. l. The sleeve 3% is clamped on the radial section ofthe pipe only a short distance inwardly from the outer flange 2t, andthe free end of the sleeve encloses a portion of the pipe nearer thecenter of the drum. The construction and disposition of the sleeve, andthe pipe apertures it encloses, may be similar to that shown in Figs. 2or 4 and need not be described in detail. Only in this instance, thefree end of the sleeve does not coincide with the terminus of theenclosed pipe, but rather the pipe extends beyond both ends of thesleeve This fact does not interfere materially with discharge of waterfrom the orifice between the sleeve and pipe, and the flow from each ofthe orifices nearly the same.

The second orifice provides the advantage of equalizing the amount ofwater discharged into the front and rear portions of the drum.Concentration of water at the rear of the drum is most apt to occurduring that portion of the drums rotation when the outer end of thepiping is and iii are at the top of the drum, for then pipe section maybe above the materials, water issuing from the end orifice is directedtoward the back of the drum and along its periphery because the pipesection 23 points in that direction.

The second orifice provided by the sleeve 34 causes water to bedischarged back along the direction of the pipe section i9 toward thecenter of the drum and near the closed, forward end thereof. As a resultthe water is more evenly distributed throughout the length of the drum,and uniform water content is more easily obtained in all portions of themix.

I claim:

1. Water injection means for concrete mixers comprising a laterallyapertured conduit having one end closed and the other end communicatingwith a source of water under pressure, and a sleeve of elasticallydeformable material enveloping the section of the conduit in which theaperture is disposed, said sleeve having a snug fit throughout itslength on said conduit except in the region of said aperture where ithas an annular inner recess surrounding the apertures, so that the waterpressure may be exerted on sumcient area of the sleeve surrounding theaperture to produce radial expansion of the sleeve and consequent axialmovement of that portion of other portions of the sleeve duringdischarge of water requisite to loosen material lodged between thesleeve and the conduit.

2. Water injection mean for concrete mixers comprising an elongatedconduit closed at one end and having a plurality of circumferentiallyali ned apertures in a section thereof remote from the closed end, saidconduit communicating with a source of water under pressure, a sleeve ofelastically deformable material enveloping the section of the conduit inwhich the apertures are disposed, the portions of the sleeve adjacentits end having a snug fit on the conduit, one end portion being closedto the passage of water be tween the sleeve and the conduit, the annularportion of the sleeve corresponding to the width of the apertures itsurrounds being inwardly recessed from the conduit to enable water pres-5 6 sure to be exerted on the entire circumferential tating discharge ofwater between the free end area, of the sleeve whereby radial expansionof th sle v and c nduit, thereof and consequent inward axial movementLOUI G, HILKEMEIER of the free end of the sleeve during the passage ofwater through the apertures and between the 5 REFERENCES CITED Sleeveand the Pondult may loosen matenal The following references are ofrecord in the lodged between said elements. t file of this patent:

3. Water injection means for concre e mixers comprising a conduit havingone end closed and UNITED STATES PATENTS the other end communicatingwith a source of {9 Number Name Date water under pressure,'.,a sleeve ofdeformable 384,306 Bourdil June 12, 1888 material tightly enclosing aportion of said con- 560,808 Macy May 26, 1896 duit, and means forclamping one end of the 887,854 Schenck May 19, 1908 sleeve on theconduit, the enclosed portion of 1,922,700 Knowles Aug. 15, 1933 saidconduit having a plurality of apertures com- 15 1,994,577 Eggert Mar.19, 1935 municating with the medial portion of the sleeve, 2,159,184Skrzynski May 23, 1939 and said sleeve having an annular inner recess2,360,344 Hilkemeier Oct. 17, 1944 surrounding said apertures affordinga reservoir 2,413,488 Draeger Dec. 31, 1946 for water issuing from saidapertures and facili-

